Investments (Tables)

9 Months Ended

Sep. 30, 2016

Investments

Schedule of marketable investments classified as held-to-maturity

Marketable investments classified as held-to-maturity consist of the following (in millions):

As of September 30, 2016	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Government-sponsored enterprises	$	44.2	$	—	$	—	$	44.2
Corporate notes and bonds	37.7		—		—		37.7
Total	$	81.9	$	—	$	—	$	81.9
Reported under the following captions on the consolidated balance sheet:
Current marketable investments	$	79.6
Noncurrent marketable investments	2.3
	$	81.9

As of December 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Government-sponsored enterprises	$	53.3	$	—	$	(0.2	)	$	53.1
Corporate notes and bonds	106.7		—		—			106.7
Total	$	160.0	$	—	$	(0.2	)	$	159.8
Reported under the following captions on the consolidated balance sheet:
Current marketable investments	$	122.0
Noncurrent marketable investments	38.0
	$	160.0

Summary of gross unrealized losses and the length of time marketable investments have been in a continuous unrealized loss position

The following table summarizes gross unrealized losses and the length of time marketable investments have been in a continuous unrealized loss position (in millions):

	As of September 30, 2016				As of December 31, 2015
	Fair Value		Gross Unrealized Loss		Fair Value		Gross Unrealized Loss
Government-sponsored enterprises:
Continuous unrealized loss position less than one year	$	—	$	—	$	48.1	$	(0.2	)
Continuous unrealized loss position greater than one year	—		—		—		—
	—		—		48.1		(0.2		)
Corporate notes and bonds:
Continuous unrealized loss position less than one year	7.0		—		63.8		—
Continuous unrealized loss position greater than one year	—		—		—		—
	7.0		—		63.8		—
Total	$	7.0	$	—	$	111.9	$	(0.2	)

Summary of the contractual maturities of held-to-maturity marketable investments

The following table summarizes the contractual maturities of held-to-maturity marketable investments (in millions):

	September 30, 2016
	Amortized Cost		Fair Value
Due in less than one year	$	79.6	$	79.6
Due in one to two years	2.3		2.3
Total	$	81.9	$	81.9